- Martino, Odino S., active 15th century1
- Martino, Vanni di1
- Mary, Blessed Virgin, Saint, in the liturgy1
- Massaran, Isaac de1
- Masses1
- Masses, Unaccompanied1
- Massi, Francesca1
- Mattei, Teo1
- Matteo, Bernardo di1
- Matteo, Giovanni di1
- Matthei, Bernardino1
- Maurice, Saint, -approximately 2871
- Maximus, of Turin, Saint, active 4th century-5th century1
- Mecco, Francesca di1
- Mecco, Xalento di1
- Medea, consort of Aegeus, King of Athens (Mythological character)1
- Medical education1
- Medici, Bernardo d'Alamanno de'1
- Medici, Giovenco de'1
- Medici, Giuliano de'1